How are the criteria for deciding divisions in plants different from the criteria for deciding the subgroups among animals?

Plants are classified based on their morphological characteristics such as :-
On the basis of their cell structure they are classified as thallophytes, bryophytes and pteridophytes.
On the basis of their visibility of seeds they are classified as gymnosperms and angiosperms.

Animals are classified on the basis of their structural variations which are taken into account such as the levels of organization, body symmetry, germinal layers, nature of coelom, segmentation and presence of notochord.